Modular, curved structure and method of assembly



March 26, 1968 T. ALFREY, JR, ETAL MODULAR, CURVED STRUCTURE AND METHOD OF ASSEMBLY Filed March 30, 1964 14 lg lg 14 5 3 15 flor/jonfa/ vflqfl) V 19 "Q Turner E Wrronuv United States Patent 3,374,588 MODULAR, CURVED STRUCTURE AND METHOD OF ASSEMBLY Turner Alfrey, Jr., and Douglas S. Chisholm, Midland,

Mich., assignors to The Dow Chemical Company, Mulland, Mich., a corporation of Delaware Filed Mar. 30, 1%4, Ser. No. 355,715 Claims. (Cl. 52-81) This invention relates to construction. It more particularly relates to a unique building and method for the preparation thereof utilizing triangular panels.

Various structures have been generated in the past utilizing triangular panels. However, in the construction of buildings having a generally cylindrical or semi-cylindrical configuration, a basic difliculty has existed in that the joints of the individual triangular panels frequently lie in a helical pattern and oftentimes in a double helical pattern of opposite hand. Such a configuration gives rise to a basic weakness in the structure which permits it to be easily deflected along such generally helical potential fold lines. The structures known to the art generally are limited to those of generally cylindrical or toroidal configuration. Further, the configuration of the triangular patterns utilized in the known structures is such that they are not economically cut from rectangular sheets which are most easily obtained commercially. In the preparation of known structures, there exists a considerable waste or scrap when the triangular plates or panels are prepared.

It is an object of this invention to provide an improved method for the fabrication of structures utilizing triangular panels.

It 'is a further object of this invention to provide an improved method of cutting such panels from a rectangular sheet.

It is a further object of this invention to provide an improved triangular structure capable of a wide variation in configuration utilizing triangular panels.

These benefits and other features and advantages of the present invention are readily achieved by providing a plurality of right triangular panels of a desired dimension, the triangular panels being of right-hand and lefthand configuration, assembling the triangular panels in such a manner that the hypotenuses of a major portion of the triangular panels are connected to and generally common to a similar side of a triangular panel of the opposite hand and a major portion of the remaining sides be connected to and common to like sides of panels of like hand and arranging the assembly of triangular panels into a desired structural configuration.

Further features and advantages of the present invention will become more apparent from the following specification when taken in connection with the drawing wherein:

FIGURE 1 depicts an arrangement for preparing triangular panels f or use in the present invention;

FIGURE 2 is an isometric view of a structure prepared in accordance with the invention;

FIGURES 3, 3a and 3b schematically represent a single panel in accordance with the invention.

FIGURES 4, 4b, 4c, 4d, 4e and 4f illustrate a panel of significant thickness.

In FIGURE 1 there is schematically illustrated a rectangular panel which is generally designated by the reference numeral 10. The rectangular panels have a face 11 and an opposing face 12. The panel is divided into a plurality of unsymmetrical or non-isosceles right-hand right triangular panels 14, and a plurality of left-hand right triangular panels 15. The surfaces 11 and 12 of the sheet are for purposes of illustration and assumed to be different.

In FIGURE 2 there is illustrated an enclosure generally designated by the reference numeral 20. The enclosure 20 has a generally semi-cylindrical configuration and is comprised of a plurality of panels 14 and 15 in contiguous edge-to-edge relationship wherein each panel 14 has positioned adjacent thereto a similar panel 14, that like sides of the panels 14 and 15 are common and the hypotenuses of axially adjacent right triangles and axially adjacent left triangles lie in a plane normal to the axis of the structure. Thus, the generally semi-cylindrical enclosure 20 of FIGURE 2 effectively is composed of a plurality of segments alternately composed of right and left-hand triangles wherein the hypotenuses form the terminal edges of the segments. That is, if a schematic flat development were to be made of each segment, it would consist of right-hand or left-hand triangles wherein the hypotenuses of alternate triangles are colinear. The assembly of the triangular panel is readily accomplished by conventional means well known to the art.

In FIGURES 3, 3a and 3b, there is schematically illustrated the dimensional relationship between a panel for a structure in accordance with the invention and the resulting dimensions and configurations of a generally cylindrical structure which may be prepared therefrom. FIGURE 3 illustrates a true plan view of the triangular panel wherein the smaller angle is designated as the height of the triangle, that is, the vertical distance from the hypotenuse to the right angle, is arbitrarily designated as unity. The larger angle is 6, the length of the hypotenuse is L which is the sum of 1 1 tan 6 tan 'y A projection of the triangular panel into a position which it would occupy when utilized as a portion of the wall of a structure is illustrated in FIGURE 3a wherein it forms an angle (1/2 with a plane tangent to the generally cylindrical configuration of the structure. The displacement of the right angle point of the triangle from this plane has the value equal to sin a/Z. A further projection of this triangular panel illustrating its relationship to the tangent plane when rotated is shown in FIGURE 3b. The projection of the shorter sides of the triangle forms angles 6' and 7', respectively, with the tangent plane. If the triangular panel is incorporated into a structure having an inscribed radius of R then a radial plane projection of the shorter side of the triangular panel subtends a central angle of 28. The longer side subtends a central angle of 2 and the perpendicular bisector of the hypotenuse bisects -an angle equal to Z-'('y'I-6'). Therefore, the following relationship exists:

dsing sin 26 cos 2% tan tan b-sm 2 tan 7 tan 7 5 Thus, for any desired dimension of a panel or structure the number of panels and their relationship to each other are readily calculated; The dotted outline in FIG- URE 4 illustrates the positioning of a mirror image configuration to provide a single panel that is both right and left hand.

Beneficially, structures in accordance with the present invention are advantageously prepared from lightweight sandwich panels such as those utilizing a rigid skin material and an expanded cellular resinous material as a core. Such panels are eminently satisfactory where minimum weight, maximum rigidity and thermal insulation values are required.

The panels may be joined by any of the techniques well known in the art including adhesives, mechanical latches or locks, splines, cap strips, and the like. Beneficial structures arealso prepared from thin panels, such as plywood, fiberboard, and the like, and are conveniently joined by the use of strips of either Wood or metal to which the panels may be nailed, screwed or adhered theretoby adhesives. The joints are readily sealed by the use of flexible tapes of the adhesive or non-adhesive variety.

Structures prepared in accordance with the invention from sandwich panel, plywood sheets, and fiberboard have been found to be exceptionally rigid and exhibit no tendency to collapse along diagonal directions, such as are some of the generally cylindrical triangular panel structures of the known art.

Structures in accordance with the present invention are readily prepared in forms other than cylindrical if the angular relationship is altered between the adjacent panels. Such configuration as pseudohemispherical and generally hemiconical are readily prepared utilizing thin sheet construction wherein the assembly is prepared utilizing flexible connections between adjacent panels;

As is apparent from the foregoing specification, the

edges of the segments, the edges of the segments being method and manufacture of the present invention is a susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. For this reason, it is to be fully understood that all of the foregoing is intended to be merely illustrative and is not to be construed or interpreted as being restrictive or otherwise limiting of the present invention, excepting as it is set forth and defined in the hereto appended claims.

We, claim:

1. A structure comprising a plurality of triangular panels, the triangular panels being of a right unsymmetrical configuration, the structure conforming generally to at least a portion of the cylindrical surface, the structure comprising a plurality of adjacent connected segments prepared from the triangular panels, adjacent segments being composed of triangular panels of opposite hand, each of the segments comprising panels of like hand wherein panels are joined to similar panels with similar disposed in a generally circumferential manner.

2. The structure of claim 1 wherein the panels are rigidly secured to adjacent panels.

3. The structure of claim 1 wherein the panels are insulating sandwich panels.

4. A method of preparing a structure which conforms generally to at least a portion of a cylindrical surface, the steps of the method comprising fabricating a plurality of panels, each of the panels having generally like dimensions and the configuration of an unsymmetrical right triangle, assembling the triangular panels in such a manner that the smaller sides of any triangular panel are connected to and generally common to a side of a like triangular panel of like hand and hypotenuses are common to panels of opposite hands, and arranging said assembly of triangular panels to provide a surface which conforms to at least a portion of a cylinder wherein assemblies of triangles of like hand form generally circumferential segments.

5. A method for the fabrication of a structure having a surface which is generally a portion of a cylindrical surface comprising assembling a plurality of unsymmetrical right triangular panels arbitrarily designated as right handed triangular panels wherein the smaller sides of any right triangular panels are connected to and generally common to a side of a like triangular panel to form a segment having two edges wherein the hypotenuses of alternate triangles form the edges of the segment and the side of intermediate length is connected to a like side of a like panel, providing a generally like segment of left handed triangular panels to provide a segment having edges, joining the edges of the segments together wherein the hypotenuses of the left handed triangular panels and the right handed triangular panels are generally contiguous, the structure comprising a plurality of such seg 'ments connected in edge to edge relationship wherein the segments are alternately composed of right handed and left handed panels, the hypotenuses of each triangular panel being generally circumferentially disposed, the remaining sides of the triangles being disposed in generally non-linear relationship with generally similar sides in adjacent segments.

References Cited UNITED STATES PATENTS 3,143,194 8/1964 Hart 52l8 X 3,144,103 8/1964 Krueger 5286 X 3,186,524 6/1965 Spaeth 5286 3,203,144 8/1965 Fuller 5281 FOREIGN PATENTS 224,317 11/ 1962 Austria.

653,204 11/1962 Canada. 1,315,078 12/1962 France.

HENRY c. SUTHERLAND, Primary Examiner.

FRANK L. ABBOTT, Examiner.

M. O. WARNECKE, Assistant Examiner. 

1. A STRUCTURE COMPRISING A PLURALITY OF TRIANGULAR PANELS, THE TRIANGULAR PANELS BEING OF A RIGHT UNSYMMETRICAL CONFIGURATION, THE STRUCTURE CONFORMING GENERALLY TO AT LEAST A PORTION OF THE CYLINDRICAL SURFACE, THE STRUCTURE COMPRISING A PLURALITY OF ADJACENT CONNECTED SEGMENTS PREPARED FROM THE TRIANGULAR PANELS, ADJACENT SEGMENTS BEING COMPOSED OF TRIANGULAR PANELS OF OPPOSITE HAND, 